05-25-2007 07:18 AM - edited 03-03-2019 05:08 PM
Imagine I want to make 3750_SWITCH pick RouterC as a path in case traffic from RouterB fails.
3550 switch:
router bgp 65123
neighbor [router b] remote-as [as #]
neighbor [router c] remote-as [as #]
neighbor [router b] route-map local-pref
route-map local-pref
set local-preference 200
Is there any drawback if I use 'local preference' attribute in order to control path the 3750_SWITCH should take ? I have been taking a look at 'Conditionally Advertising BGP Routes' as well. However, it seems to me that the 'local preference' method below should work and it is simple to implement.
If you think there is a relevant technical reason not to use the local preference method below and instead I should use BGP conditional route advertisement, please let me know.
Internet-RouterB---->3750_SWITCH<-----RouterC--Internet
I want to make 3750_SWITCH pick RouterC in case traffic from RouterB fails.
3550 switch:
router bgp 65123
neighbor [router b] remote-as [as #]
neighbor [router c] remote-as [as #]
neighbor [router b] route-map local-pref
route-map local-pref
set local-preference 200
05-25-2007 07:42 AM
Marlon
For what you are doing I believe that local preference is the better thing to do.
HTH
Rick
05-25-2007 08:04 AM
If both Router B and C advertises the same routes, you can also try to use weight. Setting a higher weight pointing to Router B.
HTH,
John
05-25-2007 02:51 PM
For your requirement, I recommend using both (local preference at the 3550 switch and conditional advertising at both routers).
Without conditional route, the routers will always advertise the default route even if their links are down, I'm assuming you don't want that.
The local preference on this case it's only assisting on the route selection of both default routes when both routers have the link up (they will both announce 0.0.0.0 back to you).
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